1. Field of the Invention
The present invention relates to a latching device for a portable computer, and more particularly to a latch assembly suitable for a portable personal computer having a thin-layer cover.
2. Related Art
Latch devices have been used in portable computers including a cover case and a main body case. Typically, the cover case of the computer is connected to the main body case through a hinge which allows the cover case to rotate about an axis within the hinge to a closed position and an open position. A user opens the cover case upward from the main body case in the open position and then uses a key board and touch pad of the portable computer while viewing a screen of a display unit. When the cover case and the main body case are in the closed position, the latch device locks the cover case and the main body case so as to cover the main body case with the cover case, to protect the keyboard of the main body case and the display unit of the cover case, and to maintain the portable computer in the closed position. When the latch is manually released, the cover can be opened. The more compact in size and relatively light in weight the portable computer has continuously evolved, the more compact and precise the latch device suitable for a thin-layer cover case and a thin-layer main body case is needed to be.
Efforts to lock the cover and the main body have spawned various types of latches. For example, U.S. Pat. No. 3,709,538 for a Latch for Receptacle issued to Seitz at al., U.S. Pat. No. 4,527,821 for a Sliding Spring Latch issued to Tanaka, and U.S. Pat. No. 4,790,579 for a Sliding Spring Latch issued to Maxwell at al. show a latch device attached to a door or cover, while U.S. Pat. No. 5,011,198 for a Handle Latch Assembly issued to Gruenberg et al. and U.S. Pat. No. 5,497,296 for an Electronic Apparatus With Hinged Display And Latch Mechanism For Releasably Latching Displays In Closed Position issued to Satou et. al. propose a latch assembly for a portable or laptop personal computer. We have found that the embodiments described by these references do not indicate that a latch claw protruding from a cover surface in a closed position can be retracted to the inside of the cover surface while in an open position.
U.S. Pat. No. 4,984,833 for a Lock Hook issued to Knurr discloses a lock hook for a door of a computer cabinet. Although the lock hook pivots about a pivot axis and projects out of a main surface in a closed position and pivots complete into an opening in the main surface of the door in a open position, the lock hook assembly, however, rotates by a complicated combination of a push rod having an sectionally circular driver, an opening area accommodating the sectionally circular driver and a substantially positive rounded portion of the lock plate contacting the sectionally circular driver. We have noticed that this reference includes a complicated latch structure which does not fit a compact and small laptop or portable computer with a small thickness.